Aoyayokogi (Japon) : Tree roots from late 10th century signal a show of power

Unearthed willow tree roots appeared in equal intervals at the Aoyayokogi ruins in Tottori Prefecture. (Provided by the Tottori Prefectural Archaeological Center)

Archaeologists have found the first evidence that trees lined an ancient road here, a possible visual display intended to flaunt state power.

Eighteen roots of willow trees from the late 10th century were unearthed in August 2015 at the Aoyayokogi ruins at intervals of 0.5 to 2 meters along a 60-meter stretch of an ancient boulevard, the Tottori Prefectural Archaeological Center said Feb. 21.

That stretch is believed to have been part of Sanindo, one of the national roads managed by the state, that was constructed from the late Asuka Period (592-710) to the early Nara Period (710-784).

“Boulevard willow trees are believed to have been planted in ‘miyako’ (ancient capital). What a surprise to find them even in rural areas as well,” said Toshihide Omi, senior cultural properties specialist of the Agency for Cultural Affairs.

“It seems that the ancient state aimed at dramatic visual effects to show off its authority by setting up the same things--boulevard trees--as in miyako,” said Omi, an authority on ancient roads.

About 40 stakes, including ones made of chestnut wood, were also uncovered in an area stretching about 100 meters. The stakes were likely splints that supported the willow trees.

According to radiocarbon dating, the tree roots and stakes on the outer side of the road site came from the late ninth century to late 10th century.

A wood strip marked “Tengyo junen” (10th year of Tengyo, or 947), which appears to be made in the 10th century, was also found.

Boulevard trees have been mentioned in Japanese literature, including Manyoshu, the oldest existing anthology of Japanese poetry dating back to the late seventh to eighth centuries.

Such trees are also believed to have been planted in Changan (current Xian), the capital of the Tang Dynasty (618-907) in China.

Last year, a painting of a group of women was found in pieces at the Aoyayokogi ruins. The painting is similar to a richly colored national treasure wall mural of a group of women found in the Takamatsuzuka Tomb in Asuka village, Nara Prefecture.